Content may be provided inside the audio
element. User agents should not show this content
to the user; it is intended for older Web browsers which do
not support audio, so that legacy audio plugins can be
tried, or to show text to the users of these older browsers informing
them of how to access the audio contents.

In particular, this content is not intended to
address accessibility concerns. To make audio content accessible to
the deaf or to those with other physical or cognitive disabilities,
a variety of features are available. If captions or a sign language
video are available, the video element can be used
instead of the audio element to play the audio,
allowing users to enable the visual alternatives. Chapter titles can
be provided to aid navigation, using the track element
and a WebVTT file. And, naturally, transcripts or other textual
alternatives can be provided by simply linking to them in the prose
near the audio element. [WEBVTT]

Returns a new audio element, with the src attribute set to the value
passed in the argument, if applicable.

Two constructors are provided for creating
HTMLAudioElement objects (in addition to the factory
methods from DOM Core such as createElement()): Audio() and Audio(src). When invoked as constructors,
these must return a new HTMLAudioElement object (a new
audio element). The element must have its preload attribute set to the
literal value "auto". If the src argument is present, the object created must have
its src content attribute set to
the provided value, and the user agent must invoke the object's
resource selection
algorithm before returning. The element's document must be
the active document of the browsing
context of the Window object on which the
interface object of the invoked constructor is found.